The tumorigenicity of immortalized cells differentiated from mouse embryonic stem cells / 中华整形外科杂志

<p><b>OBJECTIVE</b>To discuss the tumorigenicity of immortalized endothelial cells differentiated from embryonic stem cells.</p><p><b>METHODS</b>The embryoid bodies (EB) formed in vitro from embryonic stem cells, were induced to differentiate into many "round cells" (the precursor of endothelial cells). These "round cells" later formed the vascular tube-like structures. To immortalize these cells, human telomerase reverse transcriptase (hTERT) cDNA was transfected into "round cells" by lipofectin, RT-PCR and immunocytochemistry were used to evaluate the immortalized cells. And the tumorigenicity of these cells were evaluated by being injected into nude mice subcutaneously.</p><p><b>RESULTS</b>95% of these transfected cells expressed Flk-1, CD34 and vWF, and could proliferate in large quantity in vitro (cell number was doubled in 2 days, and increased 12 times in 3 days), and were able to form tubular structures.</p><p><b>CONCLUSIONS</b>These results suggest that hTERT cDNA transfection can immortalize induced endothelial cells and tumorigenicity is found after immortalized cells are injected into nude mice subcutaneously.</p>

Mechanical behavior of bionic drag reduction needle during puncturing process / 医用生物力学

Objective To design a kind of bionic drag reduction needle and investigate its mechanism of painless injection. Methods Based on the analysis of mosquito's mouthpart structure, two types of bionic drag reduction injector needles, sawtooth needle and stripe needle, were designed with the painless feature as mosquito's blood-sucking action. The injection processes of normal smooth needle and two bionic drag reduction injector needles were simulated by using explicit kinetic software LS-DYNA, and analyzed the pain-relief mechanism of bionic drag reduction needles. Results Through contrast and analysis on the stress contour, internal energy curves and resistance curves of both the smooth needle and bionic needles during the puncturing process in soft tissue, the bionic needle was found to have obvious drag reduction effects. The drag reduction rate of the saw-tooth needle and stripe needle was 23.48% and 31.57%, respectively. Conclusions The bionic needles can minimize the friction resistance to achieve the painless injection by drag reduction, and its effect is determined by the structure and shape of the bionic needle.

Preliminary comparison on the time-effect rule of pain-relieving in the treatment of moderate dysmenorrhea between acupuncture on single-point and acupuncture on multi-point / 中国针灸

<p><b>OBJECTIVE</b>To compare the time-effect rule of pain-relieving in moderate dysmenorrhea in the treatment between acupuncture on single-point and acupuncture on multi-point so as to determine the best time of needle retaining on single-point and multi-point as well as provide the reference evidences of acupuncture frequency in the treatment.</p><p><b>METHODS</b>Sixty-three cases of moderate dysmenorrhea were randomized into a single-point group (31 cases) and a multi-point group (32 cases). During the attack of dysmenorrhea, in single-point group, Shiqizhui (EX-B 8) was punctured; in multi-point group, Shiqizhui (EX-B 8), Diji (SP 8), Ciliao (BL 32) and Sanyinjiao (SP 6) were punctured and the needles were retained for 30 min. Visual Analogue Scale (VAS) values were recorded in the immediate time before acupuncture, in 5 min, 10 min, 20 min and 30 min after needle insertion, as well as in 30 min, 60 min and 120 min after needle withdrawal separately.</p><p><b>RESULTS</b>After needling, analgesia was generated rapidly in either group. During 30 min of needle retaining, analgesia was enhanced persistently till needle withdrawal in either group. In 10 min after needle insertion, the immediate analgesia in multi-point group was superior obviously to single-point group (P < 0.05) and this effect was maintained in 2 h after needle withdrawal. In 30 min after needle withdrawal, acupuncture analgesia was declined to the maximum.</p><p><b>CONCLUSION</b>Either single-point acupuncture at Shiqizhui (EX-B 8) or multi-point acupuncture at Shiqizhui (EX-B 8) and other acupoints has apparent immediate analgesia on primary dysmenorrhea of moderate degree, but the effect of multi-point acupuncture is better than that of acupuncture at Shiqizhui (EX-B 8). No matter with acupuncture at Shiqizhui (EX-B 8) or at multi-point, the time of needle retaining should not be shorten than 30 min. It is suitable to give acupuncture, twice per day for the patients with moderate and persistent pain.</p>

Identification of Chaetomium sp. CQ31 and Optimization of Xylanase Production in Solid State Fermentation / 微生物学通报

A fungus CQ31 isolated from soil samples was identified as Chaetomium sp.. This strain produced effectively xylanases utilizing several liguocellulosic materials in the solid-state fermentation (SSF), and corn straw was the best carbon source. The results of single-factor-experiment showed that the corn straw as the carbon source, tryptone as the nitrogen source, initial moisture content of 80% and initial pH 9.0 were the optimal conditions for xylanase production. Under the optimized conditions, it produced xylanase which was 4897 U/g dry substrate while mannanase was 803 U/g dry substrate after 7 days of cultivation. Therefore, xylanase and mannanase production by Chaetomium sp. CQ31 in SSF possess potential for commercial applications.

Analysis of the influence on the prognosis and safety of arginine in patients with severe trauma and burns--a multi-center randomized double blinded, placebo controlled, clinical trail in 86 patients / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the influence on prognosis and possible side-effects of arginine in</p><p><b>METHODS</b>Multi-center clinical trial, randomized double blinded patients with severe trauma and burns. and placebo control methods were employed in the study. Eighty-six patients with severe trauma and burns were randomly divided into control (C, n = 45) and arginine treatment (Arg, n = 41) groups. The patients in Arg group received arginine in dose of 0. 4 g x kg(-1) x d(-1) orally, while those in C group received same dose of placebo (tyrosine) for 7 days. All the patients in both groups were given diet with equal calories and equal nitrogen content. The changes in the wound healing time, hospital stay, and the incidence of side-effects of the medication in both groups of patients were observed and compared before and after the supplementation of arginine.</p><p><b>RESULTS</b>The wound healing time and hospital stay days of severe trauma patient in Arg group (n = 29) were 11. 1+/-2. 8 d and 19+/-6 d, which were all obviously shorter than those in C group (13. 2+/-5. 5 d, 22 +/-6 d, n =33, P <0.05). On the other hand, in severe burn patients there were no significant difference of the wound healing time (20+/-5 d vs 22+/-8 d, n = 12, P > 0. 05) and hospital stay days (28+/-6 d vs 29+/-8 d, n = 12, P >0. 05) between the Arg and C groups. In addition, in C and Arg groups, the occurrence of the side-effects were seldom (2. 44% vs 2. 22% , P = 1. 000) and it disappeared when the supplementation of drugs was stopped.</p><p><b>CONCLUSION</b>Oral feeding of arginine is beneficial in enhancing wound healing, reduction of hospital stay days in severe trauma patients and with little side-effects, but it is not beneficial to improve the prognosis of severe burn patients. Maybe this is due to inadequate number of case involved in the study.</p>

Cloning and Expression of a?-galactosidase Gene from Thermotoga maritima / 微生物学通报

The cloning and expression of a?-galactosidase gene(TM_0310)from Thermotoga maritima MSB8 was studied.The gene consists of 2019 bp,and the translated protein encodes 672 amino acids and its molecular mass is approximately 78.972 kD.The homology analysis of the deduced amino acid sequences showed that the enzyme shared 95%identity with a putative?-galactosidase from Thermotoga petrophila RKU-1 and a?-galactosidase from Thermotoga sp.RQ2.The galactosidase activity was up to 2.08 U/mg after the recombinant E.coli BL21 was induced by IPTG.The crude lysate remained about 70%activity after treated at 80℃for 10 min,indicating that the recombinant enzyme is thermostable and may be used at high temperatures.